src/pools/worker.ts

   1 import type { CircularArray } from '../circular-array'
   2 import type { Queue } from '../queue'
   3
   4 /**
   5  * Callback invoked if the worker has received a message.
   6  */
   7 export type MessageHandler<Worker extends IWorker> = (
   8   this: Worker,
   9   m: unknown
  10 ) => void
  11
  12 /**
  13  * Callback invoked if the worker raised an error.
  14  */
  15 export type ErrorHandler<Worker extends IWorker> = (
  16   this: Worker,
  17   e: Error
  18 ) => void
  19
  20 /**
  21  * Callback invoked when the worker has started successfully.
  22  */
  23 export type OnlineHandler<Worker extends IWorker> = (this: Worker) => void
  24
  25 /**
  26  * Callback invoked when the worker exits successfully.
  27  */
  28 export type ExitHandler<Worker extends IWorker> = (
  29   this: Worker,
  30   code: number
  31 ) => void
  32
  33 /**
  34  * Message object that is passed as a task between main worker and worker.
  35  *
  36  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
  37  * @internal
  38  */
  39 export interface Task<Data = unknown> {
  40   /**
  41    * Task name.
  42    */
  43   readonly name?: string
  44   /**
  45    * Task input data that will be passed to the worker.
  46    */
  47   readonly data?: Data
  48   /**
  49    * UUID of the message.
  50    */
  51   readonly id?: string
  52 }
  53
  54 /**
  55  * Worker tasks usage statistics.
  56  *
  57  * @internal
  58  */
  59 export interface TasksUsage {
  60   /**
  61    * Number of tasks executed.
  62    */
  63   run: number
  64   /**
  65    * Number of tasks running.
  66    */
  67   running: number
  68   /**
  69    * Tasks runtime.
  70    */
  71   runTime: number
  72   /**
  73    * Tasks runtime history.
  74    */
  75   runTimeHistory: CircularArray<number>
  76   /**
  77    * Average tasks runtime.
  78    */
  79   avgRunTime: number
  80   /**
  81    * Median tasks runtime.
  82    */
  83   medRunTime: number
  84   /**
  85    * Number of tasks errored.
  86    */
  87   error: number
  88 }
  89
  90 /**
  91  * Worker interface.
  92  */
  93 export interface IWorker {
  94   /**
  95    * Register an event listener.
  96    *
  97    * @param event - The event.
  98    * @param handler - The event handler.
  99    */
 100   on: ((event: 'message', handler: MessageHandler<this>) => void) &
 101   ((event: 'error', handler: ErrorHandler<this>) => void) &
 102   ((event: 'online', handler: OnlineHandler<this>) => void) &
 103   ((event: 'exit', handler: ExitHandler<this>) => void)
 104   /**
 105    * Register a listener to the exit event that will only be performed once.
 106    *
 107    * @param event - `'exit'`.
 108    * @param handler - The exit handler.
 109    */
 110   once: (event: 'exit', handler: ExitHandler<this>) => void
 111 }
 112
 113 /**
 114  * Worker node interface.
 115  *
 116  * @typeParam Worker - Type of worker.
 117  * @typeParam Data - Type of data sent to the worker. This can only be serializable data.
 118  * @internal
 119  */
 120 export interface WorkerNode<Worker extends IWorker, Data = unknown> {
 121   /**
 122    * Worker node worker.
 123    */
 124   readonly worker: Worker
 125   /**
 126    * Worker node tasks usage statistics.
 127    */
 128   tasksUsage: TasksUsage
 129   /**
 130    * Worker node tasks queue.
 131    */
 132   readonly tasksQueue: Queue<Task<Data>>
 133 }